Connections through current optical networks are either manually provisioned and remain static, and/or use electrical cross-connect switches for more automated provisioning and flexible connectivity.
Static connections are appropriate for services that are unlikely to change, and include the advantage of lowest possible loss. For high capacity networks, static connections can be rapidly provisioned into pre-planned end-to-end bands of wavelengths. For example, a wavelength division multiplexing (WDM) system may support the photonic routing of wavelengths in a group rather than individually, the group being called a waveband. An example size for a waveband is eight wavelengths. Once a waveband has been set up across the network, new wavelengths can be quickly added at the two endpoints of the previously established waveband without having to modify the network core. In this case, connections are agile at the network edge, while still static in the network core. There is also a need for connections not only edge agile, but core agile as well. Core network agility can be provided through the use of electrical cross-connect switches. However, this approach has the disadvantage of introducing numerous optical-electrical-optical conversion devices and related costs into the network. Photonic switching enables an agile optical layer, providing remote re-configuration and automated restoration.
Therefore, it is desirable to provide agility by means of photonic switching, and a seamless technique for supporting static and agile services in optical network.